F-1/A

F-1/A 1 d246655df1a.htm F-1/A F-1/A

As filed with the Securities and Exchange Commission on July 23, 2026.

Registration No. 333-297627

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

Amendment No. 1

Form F-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

C3IS INC.

(Exact name of registrant as specified in its charter)

Republic of the Marshall Islands

4412

N/A

(State or other jurisdiction of

incorporation or organization)

(Primary Standard Industrial

Classification Code Number)

(I.R.S. Employer

Identification No.)

331 Kifissias Avenue

Kifissia 14561 Athens, Greece

(Address of principal executive offices)

Dr. Diamantis Andriotis

331 Kifissias Avenue,

Kifissia 14561, Athens, Greece

Telephone: (011) (30) (210) 625 0001

Facsimile: (011) (30) (210) 625 0018

(Name, Telephone, E-mail and/or Facsimile number and Address of Company Contact Person)

Puglisi & Associates

850 Library Avenue, Suite 204

Newark, Delaware 19711

(302) 738-6680

(Name, address and telephone number of agent for service)

Copies to:

Finn Murphy, Esq.

Goodwin Procter LLP

The New York Times Building

620 Eighth Avenue

New York, New York 10018

(212) 459-7257

Matthew Bernstein, Esq.

Ellenoff Grossman & Schole LLP

1345 Avenue of the Americas, 11th Floor

New York, New York 10105

(212) 370-1300

Approximate date of commencement of proposed sale to the public: As soon as practicable after this Registration Statement becomes effective.

If any of the securities being registered on this Form are being offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933.

Emerging growth company. ☒

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards† provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☒

†	The term “new or revised financial accounting standard” refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This Amendment No. 1 (this “Amendment No. 1”) to the Registration Statement on Form F-1 (File No. 333-297627) of C3is, Inc. (the “Registration Statement”) is being filed as an exhibits-only filing. Accordingly, this Amendment No. 1 consists only of the facing page, this explanatory note, Part II of the Registration Statement, the signature page to the Registration Statement, and the filed exhibit. The remainder of the Registration Statement is unchanged and has therefore been omitted.

PART II: INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 6. Indemnification of Directors and Officers

The bylaws of the Registrant provide that any person who is or was a director or officer of the Registrant, or is or was serving at the request of the Registrant as a director or officer of another, partnership, joint venture, trust or other enterprise, shall be entitled to be indemnified by the Registrant upon the same terms, under the same conditions, and to the same extent as authorized by Section 60 of the BCA, if he acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the Registrant, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful.

Section 60 of the BCA provides as follows:

Indemnification of directors and officers.

(1) Actions not by or in right of the corporation. A corporation shall have the power to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the fact that he is or was a director or officer of the corporation, or is or was serving at the request of the corporation as a director or officer of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him in connection with such action, suit or proceeding if he acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe that his conduct was unlawful. The termination of any action, suit or proceeding by judgment, order, settlement, conviction, or upon a plea of no contest, or its equivalent, shall not, of itself, create a presumption that the person did not act in good faith and in a manner which he reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had reasonable cause to believe that his conduct was unlawful.

(2) Actions by or in right of the corporation. A corporation shall have power to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure judgment in its favor by reason of the fact that he is or was a director or officer of the corporation, or is or was serving at the request of the corporation as a director or officer of another corporation, partnership, joint venture, trust or other enterprise against expenses (including attorneys’ fees) actually and reasonably incurred by him or in connection with the defense or settlement of such action or suit if he acted in good faith and in a manner he reasonably believed to be in or not, opposed to the best interests of the corporation and except that no indemnification shall be made in respect of any claim, issue or matter as to which such person shall have been adjudged to be liable for negligence or misconduct in the performance of his duty to the corporation unless and only to the extent that the court in which such action or suit was brought shall determine upon application that, despite the adjudication of liability but in view of all the circumstances of the case, such person is fairly and reasonably entitled to indemnity for such expenses which the court shall deem proper.

(3) When director or officer successful. To the extent that a director or officer of a corporation has been successful on the merits or otherwise in defense of any action, suit or proceeding referred to in subsections (1) or (2) of this section, or in the defense of a claim, issue or matter therein, he shall be indemnified against expenses (including attorneys’ fees) actually and reasonably incurred by him in connection therewith.

(4) Payment of expenses in advance. Expenses incurred in defending a civil or criminal action, suit or proceeding may be paid in advance of the final disposition of such action, suit or proceeding as authorized by the board of directors in the specific case upon receipt of an undertaking by or on behalf of the director or officer to repay such amount if it shall ultimately be determined that he is not entitled to be indemnified by the corporation as authorized in this section.

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(5) Indemnification pursuant to other rights. The indemnification and advancement of expenses provided by, or granted pursuant to, the other subsections of this section shall not be deemed exclusive of any other rights to which those seeking indemnification or advancement of expenses may be entitled under any bylaw, agreement, vote of stockholders or disinterested directors or otherwise, both as to action in his official capacity and as to action in another capacity while holding such office.

(6) Continuation of indemnification. The indemnification and advancement of expenses provided by, or granted pursuant to, this section shall, unless otherwise provided when authorized or ratified, continue as to a person who has ceased to be a director, officer, employee or agent and shall inure to the benefit of the heirs, executors and administrators of such a person.

(7) Insurance. A corporation shall have the power to purchase and maintain insurance on behalf of any person who is or was a director or officer of the corporation or is or was serving at the request of the corporation as a director or officer against any liability asserted against him and incurred by him in such capacity whether or not the corporation would have the power to indemnify him against such liability under the provisions of this section.

Item 7. Recent Sales of Unregistered Securities

The Company issued 2,122 shares of its Common Shares and 600,000 shares of its Series A Convertible Preferred Stock to Imperial Petroleum Inc. in exchange for its contribution to the Company of all the outstanding shares of the Company’s two vessel-owning subsidiaries and $5,000,000 for working capital in conjunction with the spin-off transaction completed on June 21, 2023. These issuances were each exempt from registration as a transaction not involving an offering in the United States under Regulation S of the Securities Act.

Item 8. Exhibits and Financial Statement Schedules

Exhibit
Number

Incorporated by
Reference

Filed or Furnished

Form

Exhibit

Filing
Date

Herewith

1.1*

Form of Underwriting Agreement

3.1

Restated Articles of Incorporation of the Company, as amended by Articles of Amendment, dated April 11, 2024, to Restated Articles of Incorporation, Articles of Amendment, dated December 31, 2024, to Restated Articles of Incorporation and Articles of Amendment, dated April 3, 2025, to Restated Articles of Incorporation, dated January 23, 2026, to Restated Articles of Incorporation.

20-F

1.1

04/22/2026

3.2

Articles of Amendment to Restated Articles of Incorporation, dated April 24, 2026, to Restated Articles of Incorporation.

6-K

4.1

04/27/2026

3.2

Amended and Restated Bylaws of C3is Inc.

F-1

3.2

01/08/2024

3.3

Statement of Designation of Series A Convertible Preferred Stock

F-1

3.3

06/26/2023

4.1

Form of Class A Warrant

6-K

4.2

07/05/2023

4.2

Form of Class B-1 Warrant

6-K

4.1

01/23/2024

4.3

Form of Class B-2 Warrant

6-K

4.2

01/23/2024

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Exhibit Number		Incorporated by Reference		Filed or Furnished
		Form	Exhibit	Filing Date	Herewith

4.4	Form of Class C-1 Warrant	6-K	4.1	03/19/2024

4.5	Form of Class C-2 Warrant	6-K	4.2	03/19/2024

4.6	Warrant Agency Agreement, dated July 5, 2023, by and between the Company and Equiniti Trust Company	6-K	4.1	07/05/2023

4.7	Form of Class D Warrant	6-K	4.1	12/12/2025

4.8	Form of Class E Warrant	6-K	4.2	12/12/2025

4.9*	Form of Class F Warrant

4.10*	Form of Pre-Funded Warrant

5.1*	Opinion of Reeder & Simpson P.C.

5.2*	Opinion of Goodwin Procter LLP

10.1	Management Agreement between C3is Inc. and Brave Maritime Corp. Inc.	F-1/A	10.1	05/17/2023

10.2	Contribution and Distribution Agreement between C3is Inc. and Imperial Petroleum Inc.	F-1/A	4.2	05/17/2023

10.3	Equity Compensation Plan	F-1/A	10.2	05/17/2023

10.4	Memorandum of Agreement, dated January 16, 2026, for product tanker	20-F	4.11	04/22/2026

21.1	Significant Subsidiaries of C3is Inc.	20-F	8	04/22/2026

23.1*	Consent of Deloitte Certified Public Accountants S.A., Independent Registered Public Accounting Firm

23.2*	Consent of Reeder & Simpson P.C. (included in Exhibit 5.1)

23.3*	Consent of Goodwin Procter LLP (included in Exhibit 5.2)

24.1*	Powers of Attorney (included in the signature pages hereto)

99.1*	Reverse Stock Split Disclosure

107	Filing Fee Table				X

*	Previously filed as an exhibit on July 22, 2026.

Item 9. Undertakings

(a) The undersigned registrant hereby undertakes that:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

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(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement; Provided,

however, that paragraphs (i), (ii) and (iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That for the purpose of determining any liability under the Securities Act, each post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) To file a post-effective amendment to the registration statement to include any financial statements required by Item 8.A. of Form 20-F at the start of any delayed offering or throughout a continuous offering. Financial statements and information otherwise required by Section 10(a)(3) of the Securities Act need not be furnished, provided that the registrant includes in the prospectus, by means of a post-effective amendment, financial statements required pursuant to this paragraph and other information necessary to ensure that all other information in the prospectus is at least as current as the date of those financial statements. Notwithstanding the foregoing, with respect to registration statements on Form F-3, a post-effective amendment need not be filed to include financial statements and information required by Section 10(a)(3) of the Securities Act or Item 8.A of Form 20-F if such financial statements and information are contained in periodic reports filed with or furnished to the SEC by the registrant pursuant to section 13 or section 15(d) of the Exchange Act that are incorporated by reference in the Form F-3.

(5) That, for the purpose of determining liability under the Securities Act to any purchaser,

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a

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registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date;

(6) That, for the purpose of determining any liability of the registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form F-1 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Athens, Greece on the 23rd day of July, 2026.


C3IS INC. (Registrant)

By:		/s/ Diamantis Andriotis
Name:		Dr. Diamantis Andriotis
Title:		Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement has been signed by the following persons in the capacities indicated on July 23, 2026.


Signature		Title

/s/ Diamantis Andriotis Dr. Diamantis Andriotis		Chief Executive Officer and Director (Principal Executive Officer )

/s/ Nina Pyndiah Nina Pyndiah		Chief Financial Officer (Principal Financial Officer and Principal Accounting Officer)

* Harry N. Vafias		Director

* John Kostoyannis		Director

* George Xiradakis		Director


By:		/s/ Nina Pyandiah
Name:		Nina Pyandiah
Title:		Attorney-in-Fact

Authorized Representative

Pursuant to the requirements of the Securities Act of 1933, as amended, the undersigned, the duly authorized representative of the Registrant in the United States, has signed this registration statement on Form F-1 in the City of Newark, State of Delaware, on July 23, 2026.


		Puglisi & Associates

By:		/s/ Donald J. Puglisi
Name:		Donald J. Puglisi
Title:		Managing Director